<?hh // strict
/**
 * Copyright (c) 2014, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the "hack" directory of this source tree.
 *
 *
 */


interface X { }

function f(\HH\FormatString<X> $fs, mixed...$args) : void {
}

function _(string $s) {
  f("hello {$s} world", $s);
}
